Lock resources to prevent unexpected changes

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As an administrator, you may need to lock a subscription, resource group, or resource to prevent other users in your organization from accidentally deleting or modifying critical resources. You can set the lock level to CanNotDelete or ReadOnly. In the portal, the locks are called Delete and Read-only respectively.

  • CanNotDelete means authorized users can still read and modify a resource, but they can't delete the resource.
  • ReadOnly means authorized users can read a resource, but they can't delete or update the resource. Applying this lock is similar to restricting all authorized users to the permissions granted by the Reader role.

Note

This article has been updated to use the new Azure PowerShell Az module. You can still use the AzureRM module, which will continue to receive bug fixes until at least December 2020. To learn more about the new Az module and AzureRM compatibility, see Introducing the new Azure PowerShell Az module. For Az module installation instructions, see Install Azure PowerShell.

How locks are applied

When you apply a lock at a parent scope, all resources within that scope inherit the same lock. Even resources you add later inherit the lock from the parent. The most restrictive lock in the inheritance takes precedence.

Unlike role-based access control, you use management locks to apply a restriction across all users and roles. To learn about setting permissions for users and roles, see Azure Role-based Access Control.

Resource Manager locks apply only to operations that happen in the management plane, which consists of operations sent to https://management.azure.com. The locks don't restrict how resources perform their own functions. Resource changes are restricted, but resource operations aren't restricted. For example, a ReadOnly lock on a SQL Database prevents you from deleting or modifying the database. It doesn't prevent you from creating, updating, or deleting data in the database. Data transactions are permitted because those operations aren't sent to https://management.azure.com.

Applying ReadOnly can lead to unexpected results because some operations that don't seem to modify the resource actually require actions that are blocked by the lock. The ReadOnly lock can be applied to the resource or to the resource group containing the resource. Some common examples of the operations that are blocked by a ReadOnly lock are:

  • A ReadOnly lock on a storage account prevents all users from listing the keys. The list keys operation is handled through a POST request because the returned keys are available for write operations.

  • A ReadOnly lock on an App Service resource prevents Visual Studio Server Explorer from displaying files for the resource because that interaction requires write access.

  • A ReadOnly lock on a resource group that contains a virtual machine prevents all users from starting or restarting the virtual machine. These operations require a POST request.

Who can create or delete locks

To create or delete management locks, you must have access to Microsoft.Authorization/* or Microsoft.Authorization/locks/* actions. Of the built-in roles, only Owner and User Access Administrator are granted those actions.

Managed Applications and locks

Some Azure services, such as Azure Databricks, use managed applications to implement the service. In that case, the service creates two resource groups. One resource group contains an overview of the service and isn't locked. The other resource group contains the infrastructure for the service and is locked.

If you try to delete the infrastructure resource group, you get an error stating that the resource group is locked. If you try to delete the lock for the infrastructure resource group, you get an error stating that the lock can't be deleted because it's owned by a system application.

Instead, delete the service, which also deletes the infrastructure resource group.

For managed applications, select the service you deployed.

Select service

Notice the service includes a link for a Managed Resource Group. That resource group holds the infrastructure and is locked. It can't be directly deleted.

Show managed group

To delete everything for the service, including the locked infrastructure resource group, select Delete for the service.

Delete service

Portal

  1. In the Settings blade for the resource, resource group, or subscription that you wish to lock, select Locks.

    select lock

  2. To add a lock, select Add. If you want to create a lock at a parent level, select the parent. The currently selected resource inherits the lock from the parent. For example, you could lock the resource group to apply a lock to all its resources.

    add lock

  3. Give the lock a name and lock level. Optionally, you can add notes that describe the lock.

    set lock

  4. To delete the lock, select the ellipsis and Delete from the available options.

    delete lock

Template

When using a Resource Manager template to deploy a lock, you use different values for the name and type depending on the scope of the lock.

When applying a lock to a resource, use the following formats:

  • name - {resourceName}/Microsoft.Authorization/{lockName}
  • type - {resourceProviderNamespace}/{resourceType}/providers/locks

When applying a lock to a resource group or subscription, use the following formats:

  • name - {lockName}
  • type - Microsoft.Authorization/locks

The following example shows a template that creates an app service plan, a web site, and a lock on the web site. The resource type of the lock is the resource type of the resource to lock and /providers/locks. The name of the lock is created by concatenating the resource name with /Microsoft.Authorization/ and the name of the lock.

{
    "$schema": "https://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json#",
    "contentVersion": "1.0.0.0",
    "parameters": {
        "hostingPlanName": {
            "type": "string"
        }
    },
    "variables": {
        "siteName": "[concat('ExampleSite', uniqueString(resourceGroup().id))]"
    },
    "resources": [
        {
            "apiVersion": "2016-09-01",
            "type": "Microsoft.Web/serverfarms",
            "name": "[parameters('hostingPlanName')]",
            "location": "[resourceGroup().location]",
            "sku": {
                "tier": "Free",
                "name": "f1",
                "capacity": 0
            },
            "properties": {
                "targetWorkerCount": 1
            }
        },
        {
            "apiVersion": "2016-08-01",
            "name": "[variables('siteName')]",
            "type": "Microsoft.Web/sites",
            "location": "[resourceGroup().location]",
            "dependsOn": [
                "[resourceId('Microsoft.Web/serverfarms', parameters('hostingPlanName'))]"
            ],
            "properties": {
                "serverFarmId": "[parameters('hostingPlanName')]"
            }
        },
        {
            "type": "Microsoft.Web/sites/providers/locks",
            "apiVersion": "2016-09-01",
            "name": "[concat(variables('siteName'), '/Microsoft.Authorization/siteLock')]",
            "dependsOn": [
                "[resourceId('Microsoft.Web/sites', variables('siteName'))]"
            ],
            "properties": {
                "level": "CanNotDelete",
                "notes": "Site should not be deleted."
            }
        }
    ]
}

For an example of setting a lock on a resource group, see Create a resource group and lock it.

PowerShell

You lock deployed resources with Azure PowerShell by using the New-AzResourceLock command.

To lock a resource, provide the name of the resource, its resource type, and its resource group name.

New-AzResourceLock -LockLevel CanNotDelete -LockName LockSite -ResourceName examplesite -ResourceType Microsoft.Web/sites -ResourceGroupName exampleresourcegroup

To lock a resource group, provide the name of the resource group.

New-AzResourceLock -LockName LockGroup -LockLevel CanNotDelete -ResourceGroupName exampleresourcegroup

To get information about a lock, use Get-AzResourceLock. To get all the locks in your subscription, use:

Get-AzResourceLock

To get all locks for a resource, use:

Get-AzResourceLock -ResourceName examplesite -ResourceType Microsoft.Web/sites -ResourceGroupName exampleresourcegroup

To get all locks for a resource group, use:

Get-AzResourceLock -ResourceGroupName exampleresourcegroup

To delete a lock, use:

$lockId = (Get-AzResourceLock -ResourceGroupName exampleresourcegroup -ResourceName examplesite -ResourceType Microsoft.Web/sites).LockId
Remove-AzResourceLock -LockId $lockId

Azure CLI

You lock deployed resources with Azure CLI by using the az lock create command.

To lock a resource, provide the name of the resource, its resource type, and its resource group name.

az lock create --name LockSite --lock-type CanNotDelete --resource-group exampleresourcegroup --resource-name examplesite --resource-type Microsoft.Web/sites

To lock a resource group, provide the name of the resource group.

az lock create --name LockGroup --lock-type CanNotDelete --resource-group exampleresourcegroup

To get information about a lock, use az lock list. To get all the locks in your subscription, use:

az lock list

To get all locks for a resource, use:

az lock list --resource-group exampleresourcegroup --resource-name examplesite --namespace Microsoft.Web --resource-type sites --parent ""

To get all locks for a resource group, use:

az lock list --resource-group exampleresourcegroup

To delete a lock, use:

lockid=$(az lock show --name LockSite --resource-group exampleresourcegroup --resource-type Microsoft.Web/sites --resource-name examplesite --output tsv --query id)
az lock delete --ids $lockid

REST API

You can lock deployed resources with the REST API for management locks. The REST API enables you to create and delete locks, and retrieve information about existing locks.

To create a lock, run:

PUT https://management.azure.com/{scope}/providers/Microsoft.Authorization/locks/{lock-name}?api-version={api-version}

The scope could be a subscription, resource group, or resource. The lock-name is whatever you want to call the lock. For api-version, use 2016-09-01.

In the request, include a JSON object that specifies the properties for the lock.

{
  "properties": {
    "level": "CanNotDelete",
    "notes": "Optional text notes."
  }
}

Next steps